4 replies to this topic

[adamt117]

Hi

I have just got a smiths electric oil temp gauge and sender unit from mini sport. Does this gauge run off 12 volts or 10 volts?
because i have wired it up to the 12 volts and as soon as i switch it on the needle goes right off the other end. This is what made me think it could need 10 volts. If so does that mean i need a voltage regulator? Or is my gauge just a duff one?

Here is the gauge ive got
http://www.minisport...BT2240_05C.html

thanks

Adam

[MRA]

Did it have a wiring diagram ?

Did yo ufollow the diagram to the letter ??

Maximum deflection could be down to you wiring incorrectly or a fault, I can't imagine it would be for 10v ?? and a regulator is not a transformer it still gives 12 volts just smooth volts.

[adamt117]

It didn't come with a diagram but i have just found another one for Smiths gauges and it shows a voltage regulator before the fuel, water temp and oil temp gauges with 12 volts written before it and 10 volts after. So it looks like i need a regulator for it to work or not?

Does anyone know where to get the correct regulator for it?

[dklawson]

You can contact "Jupitus" on this board (if he is still checking in on the board). He can provide you with a solid-state one.

If he does not reply to your PM, go to eBay and search for "voltage stabilizer". While you could buy a NOS Smiths electromechanical voltage stabilizer, there are lots of solid-state options available that are much more reliable and often less money.

However, even running on a straight 12V, your new temperature gauge should not go immediately off the right end of the scale. It takes quite a while for engine oil to get up to temperature. The fact that your gauge goes right up to "hot" indicates that the sending unit wire is shorted out to earth.

That said, your post left me wondering. You stated that your gauge goes off the hot end of the scale when you turn the key. I assume that is with the engine NOT running. What does it do with the engine running? Does it drop down to cold? If so, did you buy the RIGHT sending unit and where did you fit it?

The connector on the block is NOT for oil temperature, it is a switch for oil pressure. The switch is closed when the engine is off (a path to earth that would make your gauge read overly hot) and when the engine builds oil pressure (engine running) the switch opens, breaking the path to earth. Again, what sender did you buy and where/how did you mount it?

EDIT:
I've been browsing the MiniSport web site. I did not see any listing for an electric oil pressure sending unit. The only thing I saw was their part #SMITT6811-01. Is that what you bought?

EDIT2:
It really is amazing what you can find online if you dig deep enough. On the following web site:
http://www.jensenhea...o...&forum_id=7
I found the following temperature/resistance table for the TT6811-01 Smiths sending unit.


°C 25 50 70 80 90 100 110
°F 77 122 158 176 194 212 230
Ohms 820 306 170 142 106 79 53
All plus or minus perhaps 10%

Therefore, with a cold engine and the sending unit wire disconnected, you should find about 820 Ohms between the sending unit terminal and earth. If you find much lower resistance, then the sending unit is deffective.

[adamt117]

The sender unit i have is the same as what you found (SMITT6811-01) and i have it mounted in the sump plug using this from mini sport:
http://www.minisport...o_C_MAD004.html

Thats right when i turn the ignition on it goes off the scale but i haven't tried it with the engine running.

Thanks for finding that resistance table. I will check the sender unit tomorrow to see if its faulty and go from there.

Thanks

Adam